Homepage: http://horms.net/projects/kexec/ (seems like)
There is no alternative currently in repository. You need it if you want to use kexec machinery.
Yes, GPL-2.0
I think, usage of this package is pretty limited, but very helpful.
Link to last stable sources: https://www.kernel.org/pub/linux/utils/kernel/kexec/kexec-tools-2.0.15.tar.xz